Temperature exchange between a catalytic mass in the course of regeneration and a cooling liquid



E. HOUDRY IQUID TEMPERATURE EXCHANGE BETWEEN A CATALYTIC MASS IN T HCOURSE OF REGENERATION AND A COOLING L Filed Jan. 27, 1932 Feb. 26,1935.

I JHINVENTOR 06% g BY f ATTORNEY Patented Feb, 26, 1935 UNITED STATESPATENT OFFICE 1,992,307 I TEMPERATURE EXCHANGE BETWEEN. a

CATALYTIC MASS IN THE COURSE OF REGENERATION AND A COOLING. LIQUIDEugene Houdry, Paris, France, assignor to Houdry Process Corporation,Dover, DeL, a corporation of Delaware Application January 2'1,

In France February 21, 1931 8 Claims.

. This invention relates to ways and means for controlling thetemperature of a catalytic mass during regeneration in the conversionand treatment of hydrocarbons.

Disclosures have been made in' United States pending application SerialNo. 440,199 /2' of Alfred scribe arangements for the treatment of gas orof mixtures of gas or of vapors in the presence of catalytic andrefining agents, and -for the reactivation of these agents. In theaforesaid United States application Serial No. 440,199 /2, there hasbeen described a form of construction which is characterized by thedisposition, within the catalytic or refining mass, of a pipe system(bank or coil) forthe circulation of a cooling medium, the purpose ofthis medium being to hinder excessive rise in temperature during theperiod of regeneration of the catalytic or reflning mass from thecombustion of the material deposited therein, which must be eliminatedin order to reactivate the catalytic or refining mass.

It has been discovered that, in order to obtain practical results on acommerical scale by this process of cooling, which operates within themass during the periods of regeneration, it is indispensable that asystematic exchange of calories be effected between the cooling mediumand the mass to be cooled. This systematic interchange is practicallyimpossible of realization if a gaseous fluid is employed as the coolingmedium. Indeed, such a fluid is heated progressively in the measure thatit circulates in the pipe stack of the ,exchangen-with the result thatthe walls of the latter in the end are found to be at temperatures quitevariable between the point of admission of the fluid into the apparatusand the point of exit from the latter. In order to accomplish, betweenthe gaseous fluid and the mass, through the'wall of the exchanger, anin-- 1932, Serial No. 589,134

cordance with previous usage, namely, with the pipes constantly full ofliquid.

The present invention has for its object process and apparatus which canbe employed in a manner particularly advantageous in combination withconstructions such as described and shown in the aforesaid United Statespatent applications and which overcome entirely the defects anddisadvantages referred to above.

The operation conforms to the invention, which permits in known'mannerthe use of a .heat exchanger formed by a pipe bank (in serpentine coilor otherwise), wherein circulates a liquid such, for example, as water,the stack traversing the catalytic or refining mass to be regenerated.It is characterized in that the sections in the pipe bank and the outletfor the cooling liquid are proportioned and arranged'in such a mannerthat they insure, throughout the length stantly the temperature ofebullition corresponding to the. circulation pressure.

From this fact, it follows that the temperature of thewall of theexchangeris itself maintained substantially constant throughout theextent of the bank. Each element of the bank, always maintained chargedwith liquid up to a predetermined level which permits vaporization,functions, so to smak, as a boiler tube producing steam at constanttemperature.

,With the methods employed up to this time for the circulation of agaseous-fluid or of a liquid, the cooling agent, at the expense of thesurrounding temperature, was suflicient without giving any concern tothe maintenance of a uni- 7 fect such umformity. The new proceduresolves a new problem in the particular arrangement disclosed herein, andit solves it by the indicated means, namely, by a pipe bank maintainedconstantly charged with liquid up to a conveniently determined level. Inconformity with the new arrangement, the evacuated liquid, which isunder control at its exit from the exchanger, is brought back to thefeeding manifold, the delivery of cooling water to the exchanger beingmaintained constant by the addition of water corresponding to thequantity which has been transformed into steam in the course of theadmission and evacuation cycle. 7

One form of realization of an apparatus for the application of thenew-principle'is represented in the annexed drawing, applied, by way ofexample, in combination with an apparatus element conforming to thosedescribed and shown in the aforesaid copending United States applicationSerial Nos. 505,140 and 516,159.

Fig. 1 shows such an element in side elevation, but partly cut away toshow a portion in central vertical section.

Fig. 2 is a transverse sectional view substantially on the line 22 ofFig. l.

The disclosed apparatus comprises a continuous chamber a-b withvaporization efiected in the upper portion or chamber a, catalyticcrackingtaking place in the chamber b immediately therebelow in such away that the products, whatever their degree of vaporization, passdirectly by gravity from the evaporator a into the cracking chamber 1)without any dephlegmation, and without the need of submitting them toany intermediate reheating. The contact material a may comprise anyinert porous material in lump form such as pumice stone, broken brick,or molded pieces of the porous carrier disclosed and claimed in UnitedStates Patent No. 1,818,403, issued August 11, 1931 to Alfred Joseph.The catalyst 17 is of any suitable material for effecting the desiredconversion such as broken fragments of metal, such as iron and nickel,or metallic oxides, preferably in or on a carrier such as that disclosedin the.aforesaid United States Patent No. 1,818,403, or activated claywith or without the addition of metal, metallic oxides, or other activeor non-' active substances, in the form of pellets or molded pieces, asdisclosed in my copending application, .Serial No. 600,581, filed March23, 1932. The operating temperature will depend upon the extent andcharacter of the conversion and upon the nature of the oil undergoingtransformation, but will normally be in excess of 750 F. Theregeneration of catalyst b with which the cracking chamber is charged,and the regeneration of the absorbent material a, with which thevaporizer is charged, can thus be effected simultaneously by theadmission of air under pressure into the lower chamber b. As the drawingshows, there is provided, for this purpose, an admission pipe 11 fromwhich the air is distributed by a series of conduits to all parts ofmass 1), the waste air rising throughthe contact mass a to regeneratethe latter.

Well within the mass 2) is disposed the heat exchanger, formed, by wayof example, by a serpentine coil whose horizontal elements 1 to 10,inclusive, are connected together as shown in the drawing. In the coilduring the periods of regeneration, there is caused to circulate a cool-1 ing liquid, such, for example, as water, admitted into the branch orhorizontal. element 1 by a conduit 0. From time to time, from pointshigh in the connections between the horizontal elements of the coil,lead bent conduits d and d for the steam, which discharge into acollector 6, into the lower end of which extends element 10 of the coil.Below collector e is disposed a reservoir from which condensed water isdrawn by pump g, which discharges it, by a conduit it, into the lowerendof the water feed line near the first horizontal element 1.

In accordance with the invention, the sections of the pipe elements 1 to10, inclusive, and the rate of feed from conduit 0 are established sothatthroughout the length of horizontal elements 1 to 10, inclusive,there is continuously present liquid with a free level, as indicated inFig. 2, in order to insure continuous vaporiza- The constant presence ofwater throughout the coil can be ,controlled, for example, byrestriction at the lower end of collector e. As has been pointed outabove, ,the supply of water from conduit 0 will be controlled in amanner to maintain a constant feed, the amount of feed watercorresponding to the quantity of water vaporized during the course ofthe admission and evacuation cycle.

The steam carried away by the vent pipe e from the upper end ofcollector e can be utilized in various ways.

In order to show the economy of the above described proceeding, it canbe illustrated by the following example: Apparatus-such as thatrepresented, and of which the catalyzer or refractory material charge t6be regenerated is about 900 liters, is disposed in a heater maintainedat a temperature of 450 C. Then, if one is to accomplish regeneration onan industrial scale, it is necessary to effect, during the period ofregeneration, a cooling such that the temperature in chambers aand bshall not exceed 550 C. or thereabouts. From the fact that a consanttemperature fixed at 550 is to be maintained in the mass to beregenerated, the heater in which the elements a and b are disposed beingmaintained at 450 C., a constant exchange must be effected between theregenerating mass and the heater, through the metallic wall of elementa-b, some 10,000 calories per hour. The charge of air is, in the exampleconsidered, about 84 cubic meters per hour, and thedquantity of carbonburned per hour amounts to 109% kilograms, which gives a time ofregeneration, at most, equal to the duration of the working period.During the regeneration, there is circulated on the average 120kilograms of water per hour, comprising 60 kilograms of water recoveredat the discharge of the exchanger at a temperature of 100 C. and 60kilograms of water admitted into the circulating coils. There iscollected, at the vent or evacuation conduit e, 60 kilograms of steamper hour.

In summary, the described procedure permits not only the maintenance ofa constant temperature at the walls of the exchanger elements 1 to 10,inclusive, but it effects, in comparison with apparatus disclosed in theaforesaid copending United States application Serial No. 516,159, with asystematic and regular exchange of calories, a

considerable economy in the amount of water consumed and an additionaleconomy of calories in the form of the recovered water vapor or steam.

The invention claimed is:

1. In a process for converting heavier hydrocarbons into lighterhydrocarbons involving the use of a transforming catalytic massrequiring periodic regeneration by oxidizing the contaminating materialtaken' up during an operative run and the removal of a portion of theheat of regeneration, the process steps which comprise efiectingindirect heat exchange during regeneration of the mass between the massand a cooling liquid at a plurality of substantially horizontal levelswithin and throughout the mass, and maintaining the liquid underpressure at each level while permitting vaporization of the liquid,thereby to insure heat absorption by said cooling liquid at asubstantially constant and uniform temperature all through the mass.

2. In a process for converting heavier hydrocarbons into fighterhydrocarbons involving the use of a transforming catalytic massrequiring periodic regeneration by oxidizing the contaminating materialtaken up during an operative run and the removal of a portion of theheat of regeneration, the process steps which comprise eifectingindirect heat exchange during regeneration of the mass between the massand a cooling liquid at a plurality of substantially horizontal levelswithin the mass, supplying the liquid at a predetermined rate whilepermitting vaporization of the same by the heat taken up from said mass,and venting the vapors so as to maintain the liquid under apredetermined pressure so that heat will be absorbed throughout the massby the liquid at a substantially constant temperature, namely, theboiling temperature of the liquid under the predetermined pressureconditions.

3. In a process for converting heavier hydrocarbons into lighterhydrocarbons involving the use of a catalytic mass requiring periodicregeneration by oxidizing the contaminating material taken up during anoperative run and having a pipe bank or coil embedded in said mass forthe purpose of dissipating a portion of the heat of regeneration, theprocess steps which comprise circulating a cooling liquid through saidcoil, maintaining the liquid at all parts of said coil at a levelpermitting free vaporization,

progressively venting the liquid vapors to prevent interference with themovement of the liquid and to maintain a predetermined pressure in saidcoil, condensing a portion of said vapors, and recirculating thecondensate along with fresh liquid.

4. Apparatus for the conversion of hydrocarbons comprising a chamberhaving a mass of catalytic material therein requiring periodicregeneration, means for supplying oxidizing material to said mass toeffect regeneration of the same, heat removing means in the form of aheat exchange coil embedded in said mass and having a plurality ofhorizontal sections, means for feeding liquid to said coil, and meansfor progressively venting the vapors from said coil thereby to providefor liquid in all portions of the coil at levels permitting freevaporization.

5. Apparatus for the conversion of hydrocarbons comprising a chamberhaving a mass of catalytic material therein requiring periodicregeneration, means for supplying oxidizing material to said mass toeifect regeneration of the same, heat removing means in the form of apipe bank or coil having vertically spaced horizontally extendingsections, means for admitting cooling fiuid'to the upper portions ofsaid coil, vents for certain of said sections of said coil for carryingaway vapor of said liquid, means for condensing at least a portion ofsaid vapor, and

means for discharging said condensate into the upper portions of saidcoil.

6. Apparatus for the conversion of hydrocarbons comprising a chamberhaving a mass of catalytic material therein requiring periodicregeneration, means for supplying oxidizing material to said mass toeffect regeneration of the same, heat-removing means in the form of apipebank or coil having vertically spaced horizontally extendingsections, means for admitting cooling fluid to the upper portions ofsaid coil, vents for certain of said sections of said coil for carryingaway vapor of said liquid, a collector into which said vents discharge,the lowermost of said horizontal sections of said coil leading into saidcollector, said collector having an outlet at one end thereof for vapor,and means for recirculating the condensate from the other end of saidcollector through said coil.

7. Apparatus for the conversion of hydrocarbons comprising a chamberhaving a mass of catalytic material therein requiring periodicregeneration, means for supplying oxidizing material to said mass toeffect regeneration of the same, heat removing means in the form of apipe bank or coil having vertically spaced horizontally extendingsections, means for admitting cooling fluid to the upper portions ofsaid coil, vents for certain of said sections of said coil for carryingawayvapor of said liquid, a collector into which said vents discharge,the lowermost of said horizontal sections'of said coil leading into saidcollector, said collector having an outlet at one end thereof for vapor,a reservoir beneath said collector, a conduit of restricted sizeproviding a gravity connection between said collector and saidreservoir, and means for discharging into the liquid inlet to said coilthe condensate which drains into said reservoir.

8. In apparatus for the conversion of hydrocarbons, a casing providingtwo connecting chambers in superposed relation, the upper or evaporatingchamber having a mass of absorbent material therein, the lower orcracking chamber having a mass of adsorbent catalytic material therein,means in said lower chamber for distributing air or other oxidizingsubstance throughout said catalytic mass, heat removing means in theform of a pipe bank or coil having vertically spaced horizontallyextending sections embedded in said catalytic mass, means for supplyingcooling liquid to said coil so as to maintainthe liquid in saidhorizontal sections at levels permittng free vaporization thereby toestablish during regeneration periods a temperature in all portions ofsaid coil conforming to that of the boiling point of the liquid underthe pressure conditions obtaining in said coil, means for condensing aportion of the vapor of the liquid and for recycling it through saidcoil, and means at the top of said upper casing for admitting thehydrocarbon during operating periods, and for venting theioxidizingsubstance and its products during the periods of regeneration when bothmasses are simultaneously freed of deposits from the previous workingperiod.

EUGENE HOUDRY.

CERTIFICATE or CORRECTION.

Patent No. l, 992, 307. February 26, 1935.

It is hereby certified that the name of the patentee in the abovenumbered patent should have been written and printed as Eugene J. Houdryinstead of Eugene Houdry; and that the said Letters Patent should beread with this correction therein that the same may conform to therecord of the case ,in the Patent Office.

Signed and sealed this 26th day of March, A. D. 1935.

Les l ie Frazer (Seal) Acting Commissioner of Patents.

